Wheel lifting tools and wheel jacks are used to assist operators in lifting and removing wheels or wheel-tire assemblies from vehicle axles. Conventional wheel lifting tools are inefficient because they require a significant force to be exerted by the operator to manipulate truck tires or other heavy tires and leave unsolved the problems of manipulating a heavy wheel-tire assembly after separation from the vehicle axle. See, for example, U.S. Pat. Nos. 2,619,320; 2,639,121; 2,701,707; 2,808,162; 2,857,136; and 2,904,309.
Partial solutions to the problems of removal, manipulation and replacement of heavy wheel-tire assemblies have called for the use of lifts which introduce the use of a foot pedal to lift the tire to the appropriate height so it can be replaced. Other solutions require the use of an operator's hands to lift the wheel, which puts a potentially injurious strain on the operator's back.
One remaining problem, however, is that these are not effective methods for removing or lifting wheel-tire assemblies which are extremely heavy, such as those used on heavy transport vehicles including trucks.
Another difficulty unsolved by prior approaches is that of maneuvering a heavy wheel for replacement onto an axle. The wheel usually lies flat on the ground or on a work area after being repaired and must be lifted to a vertical position. This also strains the operator's back when performed manually. In removing or replacing a wheel from a truck axle manually, the operator also runs the risk of entrapping his hands between the wheel and the axle.
Related problems also exist with removing and installing wheel-tire assemblies in conventional automobiles. But such problems are especially acute with trucks because of the bulk and weight of wheel-tire assemblies. Also, truck designs in use today complicate the removal of a tire therefrom because the wheel-tire assembly must be lifted so that it can be pulled off the axle. This contrasts with automobile wheels when the wheel-tire assembly can more readily be removed from the axle once the lug nuts are removed.